In the production of polyurethane foams, a polyol is reacted with a polyisocyanate in the presence of a polyurethane catalyst and a blowing agent. Unfortunately, certain blowing agents, namely chlorofluorocarbons (so-called "CFCs"), are hazardous to the environment, specifically the ozone layer of the atmosphere. Hence, alternatives to the use of CFC's are being actively sought by the polyurethanes community.
The use of a portable foaming apparatus employing a foam forming formulation to provide on-site generation of polyurethane foam is well-known in the art. By way of illustration, U.S. Pat. No. 3,882,052 discloses the use of such an apparatus to provide non-froth polyurethane foam. For other applications, frothed foam is suitably produced using the portable foaming apparatus by incorporating into the foam forming formulation an auxiliary CFC blowing agent, such as dichloro-difouoromethane, commercially available as FREON 12, a product of DuPont Company. When injected into the foam forming mixture, the auxiliary blowing agent serves to augment the function of the static mixer in bringing about thorough blending of the foam forming ingredients. Since the auxiliary CFC blowing agent is hazardous to the environment, alternatives to the use of CFCs in the production of frothed foam would be highly desired by frothed foams manufacturers.
Heretofore, suitable alternatives have not been known based upon the knowledge of the present inventors.